From faf907c7ba3d7df6266366556817f2ef7314640a Mon Sep 17 00:00:00 2001 From: Shine Liu Date: Tue, 25 Aug 2009 20:05:50 +0800 Subject: ASoC: S3C platform: Fix s3c2410_dma_started() called at improper time s3c24xx dma has the auto reload feature, when the the trnasfer is done, CURR_TC(DSTAT[19:0], current value of transfer count) reaches 0, and DMA ACK becomes 1, and then, TC(DCON[19:0]) will be loaded into CURR_TC. So the transmission is repeated. IRQ is issued while auto reload occurs. We change the DISRC and DCON[19:0] in the ISR, but at this time, the auto reload has been performed already. The first block is being re-transmitted by the DMA. So we need rewrite the DISRC and DCON[19:0] for the next block immediatly after the this block has been started to be transported. The function s3c2410_dma_started() is for this perpose, which is called in the form of "s3c2410_dma_ctrl(prtd->params->channel, S3C2410_DMAOP_STARTED);" in s3c24xx_pcm_trigger(). But it is not correct. DMA transmission won't start until DMA REQ signal arrived, it is the time s3c24xx_snd_txctrl(1) or s3c24xx_snd_rxctrl(1) is called in s3c24xx_i2s_trigger(). In the current framework, s3c24xx_pcm_trigger() is always called before s3c24xx_pcm_trigger(). So the s3c2410_dma_started() should be called in s3c24xx_pcm_trigger() after s3c24xx_snd_txctrl(1) or s3c24xx_snd_rxctrl(1) is called in this function. However, s3c2410_dma_started() is dma related, to call this function we should provide the channel number, which is given by substream->runtime->private_data->params->channel. The private_data points to a struct s3c24xx_runtime_data object, which is define in s3c24xx_pcm.c, so s3c2410_dma_started() can't be called in s3c24xx_i2s.c Fix this by moving the call to signal the DMA started to the DAI drivers. Signed-off-by: Shine Liu Signed-off-by: Shine Liu Signed-off-by: Mark Brown --- sound/soc/s3c24xx/s3c-i2s-v2.c | 10 ++++++++++ 1 file changed, 10 insertions(+) (limited to 'sound/soc/s3c24xx/s3c-i2s-v2.c') diff --git a/sound/soc/s3c24xx/s3c-i2s-v2.c b/sound/soc/s3c24xx/s3c-i2s-v2.c index ebfb2f6..11d8717 100644 --- a/sound/soc/s3c24xx/s3c-i2s-v2.c +++ b/sound/soc/s3c24xx/s3c-i2s-v2.c @@ -387,6 +387,8 @@ static int s3c2412_i2s_trigger(struct snd_pcm_substream *substream, int cmd, int capture = (substream->stream == SNDRV_PCM_STREAM_CAPTURE); unsigned long irqs; int ret = 0; + int channel = ((struct s3c24xx_pcm_dma_params *) + rtd->dai->cpu_dai->dma_data)->channel; pr_debug("Entered %s\n", __func__); @@ -416,6 +418,14 @@ static int s3c2412_i2s_trigger(struct snd_pcm_substream *substream, int cmd, s3c2412_snd_txctrl(i2s, 1); local_irq_restore(irqs); + + /* + * Load the next buffer to DMA to meet the reqirement + * of the auto reload mechanism of S3C24XX. + * This call won't bother S3C64XX. + */ + s3c2410_dma_ctrl(channel, S3C2410_DMAOP_STARTED); + break; case SNDRV_PCM_TRIGGER_STOP: -- cgit v1.1